P1092: NODULAR LYMPHOCYTE PREDOMINANT HODGKIN LYMPHOMA (NLPHL): HISTOLOGYCAL AND CLINICAL REVIEW IN A SINGLE CENTRE.
Authors: E. Rámila, N. Papaleo, A. Arrieta, C. Blazquez, M. Solorzano, M. Vidal, X. Vilaseca, J. Piedra, J. I. Martinez
Journal: HemaSphere (2022)

Background: NLPHL constitutes a subtype of Hodgkin lymphoma with distinct clinical characteristics and evolution. Aims: To review the histopatologycal diagnosis and clinical data in patients with NLPHL in our institution between 1999-2021. Methods: We retrospectively reviewed the histology of lymph node biopsy and clinical data, treatment and outcome of 21 adult patients consecutively diagnosed of a NLPHL between 1999 and 2021. Results: Twenty-one adult patients with diagnosis of NLPHL (3 of which presented transformation areas to diffuse large B-cell lymphoma (t-DLBCL) in the biopsy), were identified. After the histological review of the biopsies 1 patient was reclassified as diffuse large B cell lymphoma (DLBCL) and another patient as NLPLH with t-DLBCL. Six (30%) patients showed a typical histological pattern (A-B) in the biopsy whereas 14 (70%) presented histopathological variants (pattern C-F) including the 4 patients with transformation areas to DLBCL. Thus, the clinical data of a total number of 20 patients with NLPLH (4 of them with transformation areas) were reviewed. Twelve (60%) patients were males and 8 (40%) female with a median age of 46 years (range 17-79). Regarding the clinical stage at diagnosis, 9 (45%), 2 (10%), 5 (25%) and 4 (20%) were in favourable IA stage, favourable IIA stage, unfavourable I-IIA stage (according the German Study Hodgkin Group and European Organisation for Research and Treatment of Cancer criteria) and advanced III-IV stage respectively. Three of the 4 patients in advance stage presented variant histological patterns. Among the 9 patients in favourable clinical IA stage the treatment administered was the following: 2 of them didn’t receive any further treatment (in one by rejection and other patient was in surveillance after lymph node resection), 5 received Radiotherapy and 2 received combined treatment (chemotherapy with ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) and radiotherapy). The 2 patients in favourable IIA stage received combined treatment. Among the 5 patients in unfavourable I-II clinical stage, 3 received combined treatment (ABVD and radiotherapy), 1 patient was treated with ABVD and 1 with R-CHOP (rituximab, ciclophosphamide, doxorubicin, vincristine and prednisone) due to areas of t-DLBCL in the biopsy. Patients (4) in advanced stage were treated with chemotherapy: 2 with ABVD, 1 with CVP (ciclophosphamide, vincristine and prednisone) and 1 with rituximab and platinum based regimen (transformation areas to DLBCL in the biopsy and previous episode of DLBCL). Regarding to responses, 15 (83.3%) of the 18 treated patients achieved a complete remission and 3 (16.7%) were refractory (2 of them received second line therapy incuding rituximab with a complete remission). One patient relapsed; he was refractory to ABVD and achieved a complete remission with R-CHOP. With a median follow-up of 5.9 years (range 0.8-18) the overall survival is 90%; 2 patients have died (1 of them, a 79 years old patient with comorbidities, due to lymphoma). Summary/Conclusion: We have seen a 95% of concordance with the initial diagnosis after a histological review in our patients with NLPLH. 20% of the biopsies showed transformation areas to DLBCL. Most of the patients (80%) presented in a localized stage. Refractory patients responded well to antiCD20 treatment. The prognosis is good with an overall survival of 90%.